Semiautomatic pistols can be divided into various categories. Those that utilize a short-recoil action can be found in nearly all such firearms chambered for higher-powered cartridges (e.g., 9×19 mm Parabellum and above).
In short-recoil operated pistols, both the barrel and the slide move rearward together upon discharge of the firearm. Prior to the firing of the cartridge, the barrel is engaged to the slide by a locking mechanism. After firing, the recoil force drives both the slide and the barrel rearward. After the high-pressure period has passed (i.e., after the bullet has cleared the barrel), the barrel begins to disengage from the slide. The barrel travels a short distance before coming to rest, for example, forward of the magazine, and completely disengaging from the slide. The slide continues and begins extraction of the spent cartridge case using its kinetic energy and the residual gas pressure in the barrel. After extraction, the spent cartridge case is ejected and the slide continues until full travel is reached.
In short-recoil operated pistols, the barrel may be locked to the slide by a number of different types of locking mechanisms. As an example, the locking mechanism may include peripheral ribs, studs or lugs provided on the barrel. In this example, the locking mechanism may be cammed or rotated to engage and disengage the barrel with the slide. As another example, the locking mechanism may include a locking block that is separate from the barrel. In this example, the locking block may be tipped or vertically moved up and down to engage and disengage the barrel and the slide.
Accordingly, those skilled in the art continue with research and development efforts directed to barrel locking mechanisms for semiautomatic pistols.